It seems likely that one of the first references to brain herniation were by Collier1 and Alquier,2 who described cerebellar tonsillar herniation. In 1904, Collier reported:

In many cases of intracranial tumor of long duration, it was found postmortem that the posterior inferior part of the cerebellum had been pushed down and backwards into the foramen magnum and the medulla itself somewhat caudally displaced, the 2 structures together forming a cone-shaped plug tightly filling up the foramen magnum.1(p492)